Incidence of second-degree perineal laceration
Ten trials involving 3447 women were included in this outcome, 3410 women contributed data. The result of meta-analysis indicated that women in lubricant group had a lower incidence of second-degree perineal laceration when compared with those in standard care group (RR 0.72, 95%CI 0.64 to 0.82; I2=9%; moderate due to serious risk of bias) (Table 1, Figure S15).
Subgroup analyses based on lubricants type, overall risk of bias and parity were not significant subgroup effect between subgroups (Pinteraction=0.16, Pinteraction=0.50 and Pinteraction=0.97, respectively) (Figure S16, Figure S17 and Figure S18).
The result analyzed based on parity indicated that both in nulliparous women (RR 0.75, 95%CI 0.60 to 0.93; I2=25%) (Figure S18) and multiparous women (RR 0.75, 95%CI 0.60 to 0.93; I2=0%) (Figure S18) in lubricant group had statistically difference in the incidence of second-degree perineal laceration when compared with those in standard care group.